800g beef fillet centre cut
500g puff pastry
250g chestnut mushrooms (blitz to a small size or very finely chopped)
2 shallots (finely diced)
6 slices of prosciutto
25g dijon mustard
2 egg yolks and a dash of milk for an egg wash
Start by getting a large pan on a medium/high heat, season the beef fillet all round, add a small amount of oil to the pan and sear the beef fillet all over, don’t rush this as the more colour you get the better. When its nicely coloured remove from the pan and brush all over with the dijon mustard and pop into the fridge, get the same pan and return to a medium low heat and add the butter, then the shallots and sweat them down for 2-3 mins, add the thyme and the mushrooms and season well.
Turn the heat up and cook as much moisture out of the mixture as possible to ensure a better end result. When it’s looking dry remove from the pan and spread out thinly on a baking sheet and put in the fridge.
Now it’s time to build the wellington.
Take some cling film and put a few layers down onto a surface, place the slices of prosciutto down to create a sheet and then spread over the duxelles, add the beef fillet on top and then roll tightly, using the cling film to roll it into place. Put back into the fridge for 30 mins.
Then lay out a sheet of the pastry and remove the beef from the cling film and place in the centre, wrap the pastry all around trying not to overlap too much and seal it with egg wash.
Brush all over with the egg wash and do a pattern on top if you desire and return to the fridge again, you want it nicely chillies to ensure the pastry cooks properly.
While its chilling preheat your oven to 200 degrees C, when ready remove the wellington and place on a baking sheet lined with some baking parchment, place into the oven and cook for 25-30 mins or until the optimum temperature is achieved, for medium rare you want to remove it at 50 degrees C and allow to rest for 10 mins. Then you're ready to carve and serve.